Vibrator



July F. w. SIDE 2,423,524

VIBRATOR Filed Dec. 1, 1941 4 Sheets-Sheet 1 L33 f2 a: 4 30 1: VAIIPLIFIER 3 p: 40

.FIG. 4.

INVENTOR. FREDERICK W. SIDE FIG. 2. BY 5 a roan.

F. W. SIDE July 8, 1947.

VIBRATQR Filed D60. 1, 1941 @y x v V mi 1' 4 Sheets-Sheet 2 FIG. 5.

FREDERICK W. SIDE BY ORNEY.

FIG. 7.

July 8, 1947. w, $|DE 2,423,524

VIBRATOR Filed Dec. 1, 1941 4 Sheets-Sheet I5 lmimum' 6.18. INVENTOR. FREDER\CK w. 5105 Patented July 8, 1947 'VIBBATOB Frederick W. Side, Philadelphia; Pa, alsignor to The Brown Instrument Company, Philadelphia, Pa., a corporation of Pennsylvania Application December 1, 1941, No. 421,176

21 Claims.

This invention relates to electromagnetic switching means or vibrators.

The prime object of this invention is to provide an electromagnetic switching means or vibrator which can reliably over a long period of time switch small voltages such as are present in a potentiometer measuring and/or recording instrument.

More specifically an object of this invention is to provide improved electromagnetic means for operating the switching means.

(01. zoo-so) Another object is to provide improved switching means operated by the electromagnetic means.

Other objects and advantages reside in the details of construction which will become apparent upon reference to the accompanying specification, claims and drawing.

The various features of novelty which characterize this invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects obtained with its use, reference should be had to the accompanying drawings and descriptive matter in which is illustrated and described a preferred embodiment of the invention.

In the drawings:

Fig. i diagrammatically illustrates a measuring system in which the vibrators of this invention may be advantageously employed;

Fig. 2 diagrammatically illustrates one form of vibrator that may be utilized in the system of Fig. 1;

Fig. 3 diagrammatically illustrates another form of vibrator that may be utilized in the system of Fig. 1;

Fig. 4 diagrammatically illustrates another form of vibrator that may be utilized in the system of Fig. 1;

Fig. 5 is a front elevational view of a vibrator which may be of the type diagrammatically shown in Fig. 2; 1

Fig. 6 is a side elevational view oi Fig. 5:

Fig. 'l is a front elevational view of a modification of Fig. 5;

Fig. 8 is a partial front elevational view 01' a modification of Fig. 5;

Fi 9 is a front elevational view of a vibrator which may be of the type diagrammatically shown in Fig. 3;

Fig. 10 is a partial front elevational view of a modification of Fig. 9;

Fig. 11 is a front elevational view with cult.

2 removed of a vibrator which may be of the type, diagrammatically shown in Fig. 4;

18. 12 is a side elevational view of Fig. 11 with a portion oi the cover shown in section;

Fig. 13 is a top view of a portion of Figa'll and 12;

Fig. 14 is an enlarged exploded view oi the contacts and cooperating members oi Fig. 11;

' Fig. 15 is an enlarged end view of a modified contact carrying member oi Fig. 11;

Fig. 16 is an enlarged perspective view oi Fig. 15:

Fig. 17 is an enlarged elevational view partly in section of a modified part oi Fig. 11;

Fig. 18 is a partial front elevational view oi a modification oi Fig. 11;

Fig. 19 is an enlarged perspective view of a modified portion oi Fig. 18;

Fig. 20 is an enlarged perspective view of a modified portion oi Fig. 18;

Fig. 21 is a front elevational view oi a vibrator which may be oi the type diagrammatically shown in Fig. 4;

Fig. 22 is a side elevational view oi Fig. 21;

Fig. 23 is a front elevational view oi a vibrator which may be oi the type ditically shown in Fig. 4: and

Fig. 24 is a side elevational view of Fig. 23.

In Fig. l the vibrators oi this invention are diagrammatically shown. as applied to a measuring. recording and/or control apparatus which may be of the type shown, described and claimed in application Serial Number 421.173, filed by W. P. Wills on December 1, 1941. In Fig. 1, l0 designates a thermocouple responding to a condition such as a temperature condition within a furnace and which produces a D. C. or steady potential which corresponds directly with the temperature condition existing within the furnace. This D. C. potential produced by the thermocouple II is opposed by a D. C. or steady potential produced by a potentiometer circuit arrangement designated generally at II and including a slide-wire i2. v

The diiierential D. C. or steady current produced by these opposed steady potentials is controlled by a vibrator generally designated at I! and is applied to a transformer it to produce a fluctuating or alternating potential across the secondary oi the transformer it which is of one phase or of opposite phase depending upon the direction of unbalance oi the potentiometer cir- This fluctuating or alternating potential across the secondary of the transformer i4 is amthe cover plified by an amplifier generally designated at I! and the current output of the amplifier i5 is applied to a reversible electric motor generally designated at 56. The reversible electric motor l6 operates to position a contact I! along the slidewire 52. The electric motor IS in addition to operating the contact I 1 along the slide-wire I! may also position indicating and/or recording means for indicating and/or recording the temperature at the thermocouple l and in addition may operate control apparatus for controlling a condition such as the temperature affecting the thermocouple iii. The contact I] and the indicating, recording and/or control mechanism assume positions corresponding to the temperature condition existing within the furnace and to which the thermocouple it) responds.

The potentiometer circuit arrangement includes a battery 58 and a standardizing resistance i9 for applying a D. C. or steady potential across the slide-wire i2 which is in opposition to the D. C. or steady potential produced by the thermocouple it). When the contact I1 is moved to the right as shown in Fig. 1 the potential at contact 37 is increased and when the contact i1 is moved to the left it is decreased.

The vibrator i3 as diagrammatically shown in Fig. 1 includes a vibrating reed 21 carried by a support 22. The vibrating reed 2| carries a pair of contacts 23 and 23 which are adapted to engage and disengage contacts 25 and 26 upon movement of the vibrating reed. When the vibrating reed ii is stationary and in the middle position contacts 23 and 24 engage the contacts and 2B and as the vibrating reed is operated, one and then the other contact 23 and 24 disengage their respective contacts 25 and 26. The contacts may be resiliently mounted to provide this operation. The vibrator i3 includes a, coil 21 for operating the vibrating reed. Power is supplied to the coil 27 by means of a transformer 30 having a, secondary 3i connected to the coil 21' and a primary connected across line wires 33 and 36 leading from some source of alternating potential and current, not shown.

The transformer i includes a pair of primaries 3i and 33 and a secondary 39, the secondary 39 being connected to the amplifier l5. The upper end of the primary 3? is connected to the contact 26 and the lower end of the primary 38 is connected to the contact 25. The adjacent ends of the primaries El and 38 are connected to the positive element of the thermocouple Ill. The negative element of the thermocouple i0 is conn cted to the left end of the slide-wire l2 and the contact ll engaging the slide-wire I2 is connected to the vibrating reed 2|.

The reversible electric motor 16 is shown to be a rotating field type motor having a. rotor 40 provided with conductor bars and a power winding ii serially connected with a condenser 42 across the line wires 33 and 34. The condenser 32 is so selected with respect to the field winding as to produce a resonant circuit to cause the current flow through the power winding 4| to be approximately in phase with the alternating potential of the line wires 33 and 34 while permitting the alternating voltage across the power winding 4i to lead the current by substantially 90 degrees. The reversible electric motor l6 also includes a control winding 43 connected to the output of the amplifier I5. A condenser 44 is connected in parallel with the control winding 43 to provide a resonant circuit so that the alternating or fluctuating potential across the control winding 43 leads the current through the control winding 43 by substantially degrees. Power is supplied to the amplifier l3 from the line Wires 33 and 34 by wires 46 and 41, respectively. Since the details of the amplifier I! are disclosed in the above referred to Walter P. Wills application a. further description in this application is not considered necessary.

Assume now that during the first half cycle of the alternating potential applied to the line wires 33 and 34 the potential of the wire 33 is positive with respect to the potential of the wire 34 and that during the second half cycle the opposite conditions are true. Assume also that during the first half cycle the vibrating reed ii is moved to the right to cause the contact 24 to engage the contact 26 and the contact 23 to disengage the contact 25 and that during the second half cycle the vibrating reed 2! is moved to the left to cause the contact 23 to engage the contact 23 and the contact 24 to disengage the contact 26. When the potentiometer circuit is balanced, that is when the contact is a position corresponding to the value of the temperature condition within the furnace so that the potential of the contact ll is equal to that of the positive element of the thermocouple i3, no current fiows in the potentiometer circuit and, therefore, no fluctuating or alternating potential is produced across the secondary 39 of the transformer l4. Under these conditions the current flow through the control winding 33 of the reversible electric motor i5 is relatively uniform and the reversible electric motor I6 remains stationary.

Assume now that the temperature within the furnace increases to cause the potential of the positive elementof the thermocouple id to increase above theft of the contact 37. During the first half cycle of "the alternating source this unbalanced current will fiow upwardly through the primary 3! and through contacts 26 and 24 and through vibrating reed 2! to cause the upper end of the secondary 39 of the transformer to be positive with respect to the lower end. During the second half cycle this unbalanced current will flow downwardly through the transformer primary 38 and through contacts 25 and 23 and vibrating reed 2! to cause the upper end of the secondary 39 to become negative with respect to the lower end. Accordingly a fiuctuating or alternating potential is produced across the secondary 39 to cause the potential of the upper end of the secondary 39 to fluctuate in phase with the line voltage across the line wires 33 and 34. This fluctuating or alternating potential across the secondary 39 is amplified by the amplifier l5 and produces an alternating or finetuating current flow in the control winding 43 which leads the current flow through the power winding 4| by substantially 90 degrees. This causes rotation of the reversible electric motor is in a direction to move the contact ii to the right. When the contact I! is moved sufllciently far to the right so that the potential thereof corresponds to the potential of the positive element of the thermocouple iii the potentiometer circuit becomes balanced and rotation of the reversible electric motor i6 is stopped. The contact 11, therefore, assumes a position which is representative of the temperature condition then existing within the furnace.

Assume now that the temperature within the furnace decreases so that the potential of the positive element of the thermocouple Ill becomes less than the potential of the contact ll. During the first half cycle current flows through the power winding 4| by substantially 90".

vibrating reed 2| and contacts 24 and 25 downwardly through the primary 31 to cause the upper end of the secondary 33 to be negative with respect to the lower end. During the second half cycle current flows through the vibrating reed 2| and contacts 23 and 25 upwardly through the primary 35 to cause the upper end of the secondary 33 to be positive with respect to the lower end. Accordingly, an alternating or fluctuating potential is produced across the secondary 33 to cause the potential of the upper end thereof to alternate or fluctuate 180 out of phase with the line wires 33 and 34. This alternating or fluctuating potential across the secondary 39 is amplifled by the amplifier I to produce a current flow through the control winding 43 of the reversible motor l5 which lags the current fiow through the This causes the reversible motor |5 to operate in the opposite direction to move the contact H to the left to decrease the potential thereof. When the contact I1 is moved sufliciently far to the left so that the potential thereof corresponds to the potentlal of the positive element of the thermocouple |5 the potentiometer circuit becomes balanced and operation of the reversible. electric motor I5 is stopped.

The successful operation of. the above outlined system disclosed in Fig. 1 is dependent upon proper synchronizing of the vibrator l3 with re-' spect to the voltage alternations of the line wires 33 and 34, In other words, it is necessary to always cause the vibrating reed 2| to move to the right during the first half cycle when the potential of the line wire 33 is positive with respect to the potential of the line wire 34 and to cause the vibrating reed 2| to move to the left during the second half cycle when the potential of the line wire 33 is negative with respect to the potential of the line wire 34.

Figs. 2, 3 and 4 disclose schematically three types of vibrators which are properly synchronized for performing the desired mode of operation.

Referring now to Fig. 2 the vibrator 13 in addition to including the vibrating reed 2| and contacts 23, 24, 25 and 25 also includes iron cores 55 and 5| disposed on opposite sides of the vibrating reed 2 I. The coil 21 comprises a coil 21 associated with the iron core 55 and a coil 21" associated with the iron core 5|. When the coil 21 is energized a flow of flux is produced in the core 55 to attract the reed 2| to the left to cause the contacts 23 and 25 to engage and the contacts 24 and 25 to disengage. When the coil 21" is energized a fiow of fiux is produced in the core 5| to attract the reed 2| to the right to cause the contacts 24 and 25 to engage and the contacts 23 and 25 to disengage.

The coils 21' and 21" are controlled by a rectifier arranged including the transformer 30 pro vided with a, pair of secondary windings 3| and 3|" and a rectifying tube 53 having a pair of plates 54 and 55, a pair of cathodes'55 and 51 and a pair of cathode heaters 55 and 55. The cathode heaters 55 and 53 may be supplied with energy from any suitable source, not shown. The plate 54 is connected to the right end of the transformer secondary winding 3| and the left end of the secondary winding 3| is connected to the left end of the coil 21' of the vibrator. The plate a 6 and 21" are connected together and through a resistance 50 to the cathodes 55 and 51. The rectifier arrangement is, therefore, a full wave rectifier for producing a substantially steady D. C. potential across the resistance 50 which may be utilized if so desired for supplying D. C. current to the amplifier l5.

During the first half cycle of the alternating potential applied to the line wires 33 and 34 it is assumed that the left ends of the transformer secondary windings 3| and 3| are positive. Current will then fiow from the left end of the secondary winding 3|" through the plate 55. cathode 51, resistance 55 and coil 21" back to the right end of the secondary winding 3| This moves the-vibrating reed 2| to the right to cause the contacts 24 and 25 to engage and thecontacts 23 and 25 to disengage. During the first half cycle no current fiows through the coil 21' so that the vibrating reed 2| is positively attracted to the right. During the second half cycle the" right ends of the transformer secondaries 3| and 3|" are positi ye. During the second half cycle current flows from the right end of the secondary 3| through the plate 54, cathode 55, resistance and coil 21' back to the left end of the secondary 3|. This causes the vibrating reed 2| to be attracted to the left to cause the contacts 23 and 25 to engage and the contacts 24 and 25 to disengage. During the second half cycle no current flows through the coil 21" and, therefore, the vibrating reed 2| is positively attracted to the left. By reason of this rectifying arrangement as shown in Fig. 2 the operation of the vibratin reed 2| is at all times positively synchronized, ith respect to the alternations of the potentials of the line wires 33 and 34. The arrangement of Fig, 2 is shown, described and claimed in application Serial Number 421,174, filed by Walter P. Wills on December 1, 1941, which became Patent No. 2,375,158 on May 1, 1945, and, therefore, a further description of Fig. 2 is not considered necessary.

Fig. 3 shows another way of synchronizing the operation of the vibrator so that the vibrating reed 2| moves to the right during the first half cycle and to the left during the second half cycle. Coils 21' and 21" are connected in series to form a substantially continuous coil which receives current from the secondary 3| of the transformer 30. A single coil maybe used to equal advantage. The serially connected coils 21' and 21" are mounted on a core 55 and the upper end of the vibrating reed 2| is controlled by the flux passing through the core 55. A permanent magnet 55 havingasouth pole adiacent the movable end of the reed 2| and a north pole at the other end is utilized for magnetizing the vibrating reed 2| so that the upper end of the vibrating reed. as shown in Fig. 3, is always a south pole. During the first half cycle the left 55 is connected to the left end of the transformer end of the transformer secondary 3| becomes positive with respect to the right end to cause flux to flow in the core 55 to make that portion of the core 55 to the right of the vibrating reed 2| a north pole and that portion to the left a south pole. The north pole of the core 55 attracts the south pole of the reed 2| and the south pole of the core 55 repels the south pole of the reed 2| to move the reed to the right to cause the contact 24 to engage the contact 25 and the contact 23 to disengage the contact 25. During the second half cycle the right end of the secondary 3| of the transformer becomes positive with respect to the left end whereby the flux ,ing washer 9i and washer 92.

flow through the core 65 is reversed. The left side of the core 65 then becomes a north pole and the right side then becomes a south pole and these north and south poles act in com junction with the south pole of the reed 2! to move the reed 2! to the left to cause the contact 23 to engage the contact and the contact 24 to disengage the contact 26. The magnet 68 which magnetizes the reed 2| accordingly insures that the reed 2| will vibrate in synchronism with the supply voltage. Instead of utilizing the permanent magnet 66 the reed itself may be permanently magnetized for obtaining the synchronizing operation.

In Fig. 4 a permanent magnet in and an ar= mature it carried by the reed 2i is utilized for synchronizing the operation of the vibrating reed 2!. Here the coil 2'; surrounds the armature ll carried by the reed 25. The permanent magnet ll) is so arranged that the portion thereof to the left of the armature it is north pole the portion thereof to the right is a south pole. During the first half cycle the left end of the secondary of the transformer becomes positive with respect to the right end which causes t-.e upper end of the armature ii to become a north pole and the lower end a south pole. a; north pole or" the armature during the first half cycle cooperates with the north and south poles of the permanent magnet 7-9 to move the vibrating reed iii to the right to cause the contact to engage the contact 36 and the contact disengage the contact During the cycle the right end of the secondar:

es positive with respect to the e" turn causes the upper end of the a to become a south pole and the lower end a north pole. south pole of the upper of the armature cooperates with the north and south permanent magnet *5 to move the to second i of the one reed to the left to cause the contact to e; gage the contact and the contact to disengage the contact V I Since the ibrators disclosed in applicaticn Z" cular utility in connection with a potentiometer system a illustrated in Fig. i which requLes the switching of very small voltages, the details of construction of the various vibrators are extremely important. While the vibrators of this application have been specificall, designed for use in a potentiometer system of the type shown in Fig. 1, they may of course be utilized with some modification for switching larger voltages.

Figs. 5 and 6 illustrate in more detail the vibrator shown diagrammatically in Fig. 2. The laminated cores and carrying the coils Ti an 2?", respectively, are secured to a base "55 preferably made of insulating material by means of a plate '16 and screws 'il. Terminals it carried by the base 75, may be utilized for facilitating connections to the coils 21' and El". An auxiliary assembly comprising members 80 and is secured to the base '55 by means or screws 82. The various component parts of the auxiliary assembly are secured together by a screw and a nut 93 and these parts comprise a washer an insulating washer 85, connecting tab 35, member 8!, insulating washer 8?, connecting tab 28, vibrating reed 2i, insulating washer 89, member 80, connecting tab 90, insulat- By tightening the nut S3'these various component parts of theauxiliary assembly may be securely clamped together.

Spring members 94 and 95 which carry the contacts 23 and 24, respectively, are secured to the vibrating reed 2| by a. rivet 96. Outward movement of the spring members 94 and 95 is limited by the stops 91 and 98 rigidly secured to the reed 2|. The spring members 94 and 55 are channeled part way for rigidity. Preferably the contacts 23 and H are made of palladium silver. The contacts 25 and 26 are shown to be screws carried by the members and it, these screws being carried in a slot 53 formed in the members 80 and Bi. After the screws 25 and 26 are properly adjusted with respect to the contacts 23 and 24, screws I00 are tightened to securely clamp the contact screws 25 and 26 in place. Preferably the ends of the contact screws 25 and 26 carry a thin plate of iridium platinum for engagement with the palladium silver coin tacts 23 and it. During operation of the vibrator a pronounced wiping action takes place at the contacts.

The contacts 25 and 26 are normally adjusted so that when the reed 2| is in the middle position contacts 23 and 2% engage contacts 25 and 2%.. When the vibrating reed ii is moved to the right the contact 23 disengages the contact 25 and when the vibrating reed moves to the left the contact 24 disengages the contact 26. Such. an adlustment is desirable when the vibrator is utlli'ned in a potentiometer system of the type shown in Fig. i so that the D. C. potential of the potentiometer circuit is never entirely interrupted but is applied either to one or the other of the primaries 31 and 38 of the transformer it. By reason of this adjustment of the contacts '25 and 28 wear at the contacts will not appreciably affect the operation of the potentiometer system.

By making the contacts of different material, particularly of the material specified, the life of the contacts is materially increased, a clean con dition at the point of contact is at all times maintained and the performance of the contacts resubstantially uniform over long periods of operation. When two hard contacting surfaces are used it is found that each tends to wear the other and that a hard granular residue appears between the surfaces. This granular residue remains between the contacts even in the presence of a strong wiping action thereby increasing the wear of both contact surfaces. This granular residue also provides high contact resistance of an unstable character which is not suitable for switching small voltages with any degree of pre cision. When two relatively soft contacting surfaces are used it is found that there is appreciable wear and severe cutting or scoring of the contact surfaces.

These ditliculties are overcome by the use of different materials for the contacts. The iridium platinum surface of one of the contacts is highly polished to present an extremely smooth and hard surface to the mating contact. The palladium silver surface of the other contact is somewhat softer and after a number of engagements with the hard shiny iridium platinum sur face assumes a similar finish which decreases wear to a minimum thereby promoting long life to the contacts. The residue which is produced by the contacting of the contacts emanates primarily from the softer contact surface and instead of being granular and abrasive in form is a V relatively plastic. The wiping action of the concleaning the contacts for optimum performance. Any wear that does take place, takes place at the palladium silver surface and does not destroy the reference surface of the iridium platinum contact. When the contacts are originally ad- Justed the iridium platinum surfaces form the reference surfaces. The symmetry of adjustment of the two sets of contacts, therefore. remains the same over long periods of operation to provide uniform operation.

Fig. 7 illustrates a modification of the arrangement of Figs. 5 and 6. Instead of the laminated cores 50 and 5I of Fig. 5, Fig. 7 utilizes a single laminated core structure having legs I05 and I06 and I01, the coil 21' being mounted on the leg I05 and the coil 21" being mounted on the leg I01. The laminated core structure is secured to the base 15 by means of a plate I03 and screws I09. The auxiliary assembly including the members 90 and 3| is exactly the same as the auxiliary assembly of Fig. 5 and like reference numbers for like parts have been utilized. The vibrating reed 2I of Fig. 7 carries an armature IIO constructed on a radius and the armature I I cooperates with the ends of the legs I05, I03 and I01. The armature IIO also acts as stops for restraining the movement of the spring members 94 and 95. When the coil 21" is energized the armature H0 and the vibrating reed 2I are moved to the right and when the coil 21' is energized the armature H0 and reed 2I are moved to the left.

Fig. 8 shows a further modification of Fig. and is exactly the same as Fig. 5 with the exception of the members which carry the contacts 23 and 24. In Fig. 8 the contacts 23 and 24 are carried by spring members H2 and H3, respectively, which are suitably riveted to the vibrating reed 2I by rivets H4. The operation of the contacts of Fig. 8 is substantially the same as the operation of the contacts of Fig. 5.

Fig. 9 illustrates in more detail the vibrator diagrammatically shown in Fig. 3. In Fig. 9 the laminated core 05 is secured to the base by means of a plate H5 and screws III. The core '85 carries the coils 21' and 21" and suitable terminals 13 carried by base 15 may also be utilized for facilitating connections to the coils 21' and.

sidered necessary. The vibrating reed 2I carries a pair of relatively short, stiff spring members H1 and I I0 which are suitably secured to the vibrating reed 2I by rivets H9. The contacts 23 and 24 are carried by the spring members I I1 and H3, respectively, and cooperate with the stationary contacts 25 and 20. The operation of the contacts of Fig. 9 is substantially the same as the operation of thecontacts of Fig. 5. The permanent magnet 66 is imbedded in the base 15 immediately adjacent the vibrating reed 2| so that the permanent magnet 66 operates to polarize the vibrating reed iii to perform the operation outlined above in connec ion with Fig. 3. As pointed out above the same operation could be ob tained by ma netizng the vibrating reed 2 I, and l mi ating the magnet 63.

Fi shows a mo i cation of the arrangement of Fig. 9 the main distinction bein the construction of the members which carry the contacts 23 and 24. This construction is substantially Y 10 the same as the construction of Figs. 5 and 7. Here spring members 34 and 95 carrying the contacts 23 and 24 are secured to the vibrating reed 2I by a rivet 93. The armature I2| which is Dolarized by the magnet 04 or which may be permanently magnetized cooperates with the core 35 for synchronizing the operation of the vibrator. Armature I2 I also operates as a stop for the spring members 94 and 34.

The spring members carrying the contacts 23 and 24 shown in Fig. 9 could be utilized in Figs. 5 and 'l and also the spring members carrying contacts 23 and 24 shown in Fig. 8 could be utilized in the arrangement of Fig. 9. All of the above described vibrators may be provided with suitable oovers to protect them from dirt and corrosive atmospheres.

Figs. 11 to 13 show in more detail the vibrator schematically shown in Fig. 4. Referring more specifically to Figs. 11 and 12 a base preferably formed of insulating material is shown at I25 and secured to this base are six terminals I25, I21, I20, I29, I and I 3| which adapt the vibrator for mounting in a conventional tube socket. The various electrical connections from the vibrator are made through these terminals. A supporting plate I32 is secured to the base I25 by means of screws I33. One of the screws I33 carries a tab I34 which is suitably electrically connected to the terminal I3I for grounding the plate I32 and the various parts carried thereby. The magnet 10 is carried by the plate I32 and this magnet may be formed of aluminum. nickel and cobalt in jpro-' portions commonly termed "Alnico. Referring to Fig. 13 it is seen that the magnet 10 is' tapered at I33 for the purpose of concentratin the flux of the magnet at I31 adjacent the armature II. The coil 21 formed in a Bakelite mold extends into the opening of the magnet 10 and is held in place by a bracket I39. The bracket I39 is preferably formed of soft steel and is provided with ears,I40 for mounting purposes. Screws I4I extend through the ears I40 and through suitable openings in the magnet 10 for holding the bracket I39, the coil 21 and the magnet 10 in place on the plate I32. The bracket I39 is provided with relatively short ears I42 and relatively long ears I43 for clamping the coil 21 rigidly in place. The relatively long ears I43 cooperating with the remainder of the bracket I33 operate to provide a flux path for the flux produced by the coil 21 and to shield the rest of the vibrator from the magnetic strays produced by the coil 21. The plate I32 is provided with openings I44 for accommodating wires which connect the coil 21 to the terminals I23 and-I33.

A bifurcated stud I40 having a screw threaded extension I43 extending through an opening in the plate I32 is held in place on the plate I32 by a nut I50 cooperating with the screw threaded extension I49. The bifurcated end of the stud I43 includes a stacking more clearly shown in Fig. 14. The stacking is held in place In the bifurcated stud I43 by means of a screw I5I and a cooperating nut I52. The stacking as shown in Fig. 14 includes an insulating washer I53, a connecting tab I54, a spring contact member I55. a spring stop III I55, an insulating washer I51, a connecting tab I53, the vibratin reed 2I, an insulating washer I59, a. spring stop I93, a spring contact member insulates the stacking from the screw III. The insulating washers I53, I51, I53 and I63 are preferably made of mica. The spring contact members I56 and I H are preferably madeoi' beryllium copper tempered. The spring stops I56 and I60 are preferably made of spring brass and the vibrating reed 2i is preferably made of beryllium copper tempered. The connecting tabs I54, I60 and I62 are preferably made of cadmium plated copper and as noted in Fig. 14 these connecting tabs are turned over at the ends to facilitate electrical connections. The tab I54 acts as a terminal for the spring contact member I55, the tab I58 acts as a terminal for the vibrating reed 2i and the tab I62 acts as a terminal for the spring contact member I6i. The tabs I62, I58, and I66 are, respectively, connected to the terminals I28, I26 and I28. The spring stops I56 and I60 are provided with a circular opening I61 and a rectangular opening I613. The upper ends of the spring contact members I55 and I 6i are channeled as shown at I63 and the contacts 26 and 25 extend through openings in the spring contact members E55 and I6i and are held in place in the channei. When the contacts 26 and 25 are suitably positioned in the channels, they are soldered in place, the soldered connection between the contacts and the channels forming a rigid and stable mounting for the contacts 26 and 25. The channel arrangement I68 also limits all pivotal or pending movement in the spring contact members I55 and I62 the flattened portion below the channel. The vibrating reed 2i carries the contacts 23 and 24 which engage and disengage the contacts 25 and 26 carried by the spring contact members I6i and I56, respectively. The contacts 26 and 26 extend through the rectangular openings I66 of the spring stops I56 and I60.

A pair of bifurcated studs I10 and I'll are riveted to the plate I32 and screw threadedly mounted in the bifurcations of these studs are adjustable stops I12 and I13, respectively. Preferably these adjustable stops I12 and I13 are formed of an insulating material such as Isolantite." Screws I It and I15 may be tightened for clamping the Isolantite screws in their adjusted positions. The upper end of the reed 2i carries the armature II which may be formed of "Armco iron or Swedish steel.

When the vibrator is assembled as shown in figs. 1i and 12 the spring stops I60 and I56 are engaging the adjustable stops I12 and I13 and the channel portions I68 of the spring contact members I 6.- and I55 are engaging the spring stops I50 and I56 between the openings I61 and 56%. The contacts 25 and 26 both engage the contacts 23 and 2 when the vibrating reed 2i is in the middle position. By adjusting the adjustabie stops i155 and I13 the positions of the contacts 25 and 26 with respect to the contacts 23 and it may be adjusted.

as the vibrating reed 2i moves to the right contact 23 disengages contact 25 and contact 26 causes the channel portion I66 of the spring contact member i55 to disengage the spring stop I 56. When the vibrating reed 2i moves to the left the same operation in reverse order takes place. The channel portion I68 has substantially the same contact surface with the spring stop I56 as the surface of the contact 26 with the contact 26 so that wear on the contact 26 and on the channel portion I68 will be substantially the same. The wear on the channel portion I66 compensates for the wear on the contact 26 so that the contacts as and 26 keep their same relative positions and readjustment of the contact 26 with respect to the contact 24 fter a long period oi operation is not necessary. The same is true for the contacts 23 and 25 and the channel portion I68 of the spring contact member I6I. Due to the fact that bending of the spring contact members I55 and IN must take place below the channel portion I68 the movement of the contacts 25 and 26 when engaged by the contacts 23 and 25 is limited to an arc whereby reliable-operation is assured and a good wiping action at the con tacts is provided, Preferably the contacts 23 and 24 are formed of iridium platinum and the contacts 25 and 26 are formed of a palladium silver to provide improved operation as pointed out above in connection with Fig. 5.

During the operation of the vibrator of Fig. 11 the armature 1i cooperates with the concentrated flux at the point I31 of the magnet 10. Changing of the upper end of the armature II from a north pole to a south pole by the operation of the coil 21 is enhanced by the ears I43 f the bracket I39 and the bracket I39 itself and this taken in conjunction with the concentrated flux of the magnet at I31 provides a very efficient mode of operation.

The operating parts of the vibrator mechanism are preferably sealed within a casing I11 portion of which is shown in Fig. 12. The casing I11 engages a gasket I18 which may be made of cork for hermetically sealing the operating parts in the casing I11. A clamping ring I19 secures the casing I11 and gasket I16 to the base I25.

Figs. 15 and 16 show a modified form of spring contact member. Here the spring contact member is shown at I6I and is provided with a dinerent type of channel I62. The purpose of the channel I02 in Figs. 15 and 16 is to strengthen the spring contact member and to limit the bending movement of the spring contact member IBI to a point below the channel. The spring contact members IBI of Figs. 15 and 16 may be substituted for the spring contact members I55 and I6I of Fig. 11.

Instead of utilizing Isolantite" stops I12 and I13 of Fig. 11 a modified stop such as shown in Fig. 1'! may be used. In Fig. 17 this modified stop comprises a metal screw I which may be screw threadedly mounted in the studs I10 and I It. The metal screw I65 is drilled out at one end and a. glass gob I86 is suitably secured in the drilled out portion, The glass gob acts as the stop for the spring stop members I60 and I56 and also acts as an insulating material in the same way that the Isolantite stops I12 and 12- act.

Fig. 18 illustrates a modification of Fig. 11 the only difference being the type of adjustable stops utilized for adjusting the spring stops I60 and I56. These adjustable stops comprise screws I89 and I60 carrying pins I9I and I92 eccentrically located thereon and provided with suitable insulation. By rotating the screws I36 and I 90 the pins I6I and I02 are laterally positioned for adjusting the positions of the spring stops I60 and I56.

Fig. 19 illustrates a modified form of contact arrangement. The vibrating reed 2I carries an elongated contact 23 which is engaged by an elongated contact 25 formed on a spring member I94. The purpose of the elongated contacts 23 and 24 is to present a large contact area but still being sufficiently small in depth to prevent foreign material from lodging therebetween.

F g. 20 is substantially the same as Fig. 19 with the exception that the spring member |04 is formed of a plurality of strips as shown at I05. The contact 24, therefore, is formed of a. plurality of smaller contacts all spring biased into en agement with the contact 23 thereby assuring complete contact throughout its entire surface with the contact 23.

Figs. 21 and 22 show a modified arrangement of a vibrator of the type schematically shown in Fig. 4 and shown in more detail in Fig. 11. A pair of posts 200 and 20l carry brackets 202 and 203 by means of screws 204 and the brackets 202 and 203 are secured to the base I25 by screws 205. The upper ends of the posts 200 and 20| carry a pair of magnets 208 and 201 and screws 208 secure the magnets to the posts. The coil 21 is carried by the magnets 205 and 201 and the armature 1| of the vibrating reed 2| operates within the coil 21 and between the magnets 206 and 201. The stacking which is exactly the same as the stacking in Fig. 11 is carried between the posts 200 and 20| by spacers 209 and 2|0 the parts being held in assembled relation by a screw 2H and a cooperating nut 2l2. The posts 200 and 20| are provided with a slot 2|3 in which are adjustably mounted the adjustable stops I12 and H3. Screws 2|4 mounted in the posts 200 and 20| clamp the adjustable stops I12 and I13 in their adjusted positions. The vibrator of Figs. 21 and 22 operates in substantially the same manner as the vibrator of Fig. 11 and, therefore, a further description is not considered necessary.

'. In Fig. 23 a plate 220 is secured to the base 125 by nuts 22| cooperating with studs carried by the base. A magnet 222 is mounted on one side of the plate 220 by a screw 223 and the coil 21 is mounted on the other side of the plate 220. The coil 21 is carried by a bracket 224 which is suitably secured to the plate 220 by means of screws 225. The upper 'end of the plate 220 carries a bifurcated stud 221 held in place by a nut 221'. The bifurcated stud 221 carries the vibrating reed 2| and spring contact members- 220v and 229 the members being electrically separated by suitable insulating washers. The parts are clamped together in the stud 221 by a screw 221A and a cooperating nut 2213. The spring contact members 228 and 223 carry the contacts 25 and 26, respectively, which cooperate with the contacts 23 and 24 carried by the vibrating me, it will be apparent to those "skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit of this invention as set forth in the appended claims, and that in some cases certain features of this invention may sometimes be used to advantage without a corresponding use of other features.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

reed 2|. Screws 230 and 23| carry eccentrlcally located pins 232 and 233 which are utilized for the purpose of adjusting the contacts 25 and 25 with respect to the contacts 23 and 24.

The vibrating reed 2| is provided with an extension 235 which extends through an opening 230 in the plate 220 to a point adjacent the magnet 222. The lowerend of the vibrating reed 2| is provided with an armature 231 which extends through an opening 230 in the plate 220 to a point adjacent the magnet 222. During one half cycle the armature 231 becomes a north pole and during the other half cycle it becomes a south pole and cooperates with the north and south poles of the magnet 222 to cause vibrating reed 2| to operate. The extension 235 of the vibrating reed 2| assists in completing the path for the magnet flux. The operation of the vibrators of Figs. 23 and 24 is substantially the same as those of Figs; 4, 11 and 21 and, therefore, a further description is not considered necessary.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of this invention now known to 1. In combination, a relatively stationary contact, a movable contact for engaging and disengaging at frequent intervals the relatively stationary contact, one of the contacts being provided with a polished platinum iridium surface, and the other contact being provided with a palladium silver surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith.

2. In combination, a relatively stationary contact, a movable contact for engaging and disengaging at frequent intervals the relatively stationary contact, means for resiliently mounting one of the contacts to provide a wiping action as the contacts engage and disengage, one of the contacts being provided with a polished platinum iridium engaging surface, and the other contact being provided with a palladium silver engaging surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith.

3. In combination, a relatively stationary contact, a movable contact for engaging and disengaging at frequent intervals the relatively stationary contact, means for adjusting one of the contacts with respect to the other, one of the contacts being provided with a polished platinum iridium engaging surface, and the other contact being provided with a palladium silver engaging surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith.

4. In combination, a relatively stationary contact, a movable contact for engaging and disengaging the stationary contact, electromagnetic means for operating the movable contact at frequent intervals, one of the contacts being provided with a polished platinum iridium engaging surface, and the other contact being provided with a palladium silver engaging surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith.

5. In combination, a pair of relatively stationary contacts, a pair of movable contacts for engaging and disengaging at frequent intervals the pair of relatively stationary contacts, means for independently adjusting the contacts of the relatively stationary pair with respect to the pair of movable contacts, one pair of contacts being provided with polished platinum iridium en-.-

gaging surfaces, and the other pair being provided with palladium silver engaging surfaces which mateprecisely with the polishedv platinum gagement therewith.

6. In combination, a relatively stationary contact, a movable contact for engaging and disengaging at frequent intervals the relatively stationary contact, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and biased to move the relatively stationary contact toward the movable contact and to permit movement of the relaeat contacting surfaces of the relatively stationary contact and the movable contact that the wear at the contacting surfaces is substantially the same whereby the relative positions of the relatively stationary contact and the movable contact remain substantially the same regardless of wear.

7. In combination, a relatively stationary contact, a movable contact for engaging and disengaging at frequent intervals the relatively stationary contact, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and biased to move the relatively stationary contact toward the movable contact and to permit movement of the relatively stationary contact in the opposite direction when it is engaged by the movable contact, and a stop for limiting the movement of the spring arm and the relatively stationary contact toward the movable contact, said spring arm being ribbed throughout a portion of its length to strengthen the ribbed portion and to limit bending of the spring arm to the unribbed portion whereby a wiping action is produced between said movable and relatively stationary contacts.

8. In combination, a pair of relatively stationary contacts, a pair of movable contacts for em gaging and disengaging at frequent intervals the pair of relatively stationary contacts, a pair of spring-arms fixed at one end and each carrying one of the pair of relatively stationary contacts near the other end and biased to move the relatively stationary contacts toward the movable contacts and to permit movement of the relativeiy stationary contacts in the opposite direction when they are engaged by the movable contacts, a pair of stops for limiting movement of the spring arms and the relatively movable contacts toward the movable contacts, the contacting surfaces of the spring arms and the stops being so related to the contacting surfaces of the relatively stationary contacts and the movable contacts that the Wear at the contacting surfaces is substantially the same whereby the relative positions of the relatively stationary contacts and the movable contacts remain substantially the same regardless of wear.

9. In combination, a pair of relatively stationary contacts, a pair of movable contacts for engaging and disengaging at frequent intervals the pair of relatively stationary contacts, a pair of spring arms fixed at one end and each carrying one of the pair of relatively stationary contacts near the other end and biased to move the relatively stationary contacts toward the movable contacts and to permit movement of the relatively stationary contacts in the opposite direction when they are engaged by the movable contacts, a pair of stops for limiting movement of the spring arms and the relatively movable contacts toward the movable contacts, said spring arms being ribbed throughout a portion of their lengths to strengthen the ribbed portions and to limit bending of the spring arms to the unribbed portions whereby a wiping action is produced between said movable and relatively stationary contacts.

10. In combination, a pair of relatively stationary contacts, a pair of movable contacts for engaging and disengaging at frequent intervals 16 the pair of relatively stationary contacts, a pair of spring arms fixed at one end and each carrying one of the pair of relatively stationary contacts near the other end and biased to move the relatively stationary contacts toward the 11. In combination, a resilient reed fixed at one end and movable at the other end, a permanent magnet located in its entirety alongside of the edge of the movable end of the resilient reed with its poles adjacent the movable end of the resilient reed, a coil surrounding the resilient reed adjacent its movable end for alternately reversing the polarity of the movable end of the resilient reed for vibrating the resilient reed, a contact remotely located from said permanent magnet and coil and carried by said resilient reed and moved thereby, a relatively stationary contact engaged and disengaged by the movable contact, a spring member carrying the relatively stationary contact and biased to move the relatively stationary contact toward the movable contact, a stop for limiting movement of the spring member and the able reed but permitting the movable contact to move the spring member and the relatively stationary contact in the opposite direction.

12. In combination, a resilient reed fixed at one end and movable at the other end, a permanent magnet located in its entirety alongside of the edge of the movable end of the resilient reed with its poles adjacent the movable end of the resilient reed, a coil surrounding the resilient reed adjacent its movable end for alternately reversing the polarity of the movable end of the resilient reed for vibrating the resilient reed, a contact remotely located from said permanent magnet and coil and carried by said resilient reed and moved thereby, a relatively stationary contact engaged and disengaged by the movable contact, a spring member carrying the relatively stationary contact and biased to move the relatively stationary contact toward the movable contact, a stop for limiting movement of the spring member and the contact toward the movable reed but permitting the movable contact to move the spring member and the relatively stationary contact in the opposite direction, and a member adjacent the coil for producing a low resistance 13. In combination, a relatively stationary contact, a movable contact for engaging and disengaging at frequent intervals the relatively stationary contact, one of the contacts being provided with a polished platinum iridium engaging surface and the other contact being provided a palladium silver engaging surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and biased to move the relatively stationary contact toward the movable contact and to permit movement of the relatively stationary contact in the opposite direction when it is engaged by contact toward the mov-.

17 the movable contact, and a stop for limiting movement of the spring arm and the relatively Stationary contact toward the movable contact..

14. In combination, a resilient reed fixed at one end and movable at the other end. a Permanent ma net located in its entirety alon sid oi the edge or the movable end of the resilient reed with its poles adjacent the movable end of the resilient reed, a coil surrounding the resilient reed adjacent its movable end for alternately reversing the polarity of the movable end of the resilient reed for vibrating the resilient reed, a

relatively stationary contact, a movable contact remotely located from said permanent magnet and coil and operated by the resilientreed for enand coil and operated by the-resilient reed forengaging and disengaging the relatively stationary contact, one of the contacts being provided with a polished platinum iridium engaging surface and the other contact being provided with a palladium silver engaging surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith.

16. In combination. a resilient reed fixed at one end and movable at the other end, a permanent magnet located in its entirety alongside of the edge of the movable end of the resilient reed with its poles adjacent the movable end of the resilient reed, a coil surrounding the resilient reed adjacent its movable end for alternately reversing the polarity of the movable end of the resilient reed for vibrating the resilient reed, a relatively stationary contact, a movable contact remotely located from said permanent magnet.

and coil and operated by the resilient reed for engaging and disengaging the relatively stationary contact, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and biased to move the relatively stationary contact toward the movable contact and to permit movement of the relatively stationary contact in the opposite direction when it is engaged by the movable contact, and a stop for limiting movement of the spring arm and the relatively stationary contact toward the movable contact.

17. In combination, a resilient reed fixed at one end and movable at the other end, a permanent magnet located in its entirety alongside of the edge of the movable and of the resilient reed with its poles adjacent the movable end of the resilient reed, a coil surrounding the resilient reed adjacent its movable end for alternately reversing the polarity of the movable end of the resilient reed for vibrating the resilient reed, a relatively stationary contact, a movable contact remotely located from said permanent magnet and coil and operated by the resilient reed for engaging and disengaging the relatively stationary contact, one of the contacts being provided with a polished platinum iridium engaging surface and the other contact being provided with a palladium silver engaging surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and biased to move the relatively stationary conmovement of the relatively stationary contact in the opposite direction when it is engaged by the;

movable contact, and a stop for limiting moveinent of the spring arm and the relatively stationary contact toward the movable contact.

iii. In combination, a resilient reed fixed at one end and movable at the other end, a permanent magnet located in its entirety alongside of the edge of the movable end of the resilient reed with its poles adjacent the movable end of the resilient reed, a coil surrounding the resilient reed adjacent its movable end for alternately reversing the polarity of the movable end of the resilient reed for vibrating the resilient reed, the permanent magnet being reduced in cross section at the poles for concentrating the fiux produced thereby at the movable and of the resilient reed, a relatively stationary contact, a movable contact remotely located from said permanent magnet and coil and operated by the resilient reed for engaging and disengaging the relatively stationary contact, one of the contacts being provided with a polished platinum iridium engaging surface and the other contact being provided with a palladium silver engaging surface which mates precisely with the polished platinum iridium surface upon repeated engagement therewith, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and biased to move the relatively stationary contact toward the movable contact and to permit movement of the relatively stationary contact in the opposite direction when it is engaged by the movable-contact, and a stop for limiting the movement of the spring arm and the relatively stationary contact toward the movable contact, said spring arm being ribbed throughout a 'portion of its length to strengthen the ribbed portion and to limit bending of the spring arm to the unribbed portion, the contacting surfaces of the spring arms and the stops being so related to the contacting surfaces of the relatively stationary contacts and the movable contacts that the wear at the contacting surfaces is substantially the same whereby the relative positions of the relatively stationary contacts and the movable contacts remain substantially the same regardless of wear, and a member adjacent the coil for producing a low resistance path for the flux produced by the coil and for shielding the contacts from magnetic strays produced by the coil.

19. In combination, a relatively stationary contact, a movable contact for engaging and disengaging the relatively stationary contact, electromagnetic means for operating the movable contact at frequent intervals, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and biased to move the relatively stationary contact toward the movable contact and to permit movement of the relatively stationary contact in the opposite direction when it is engaged by the movable contact, and a stop for limiting the movement of the spring arm and the relatively stationary contact toward the movable contact, the contacting surfaces of the spring'arrn and the stop being so related to the contacting surfaces of the relatively stationary contact andvthe movable con- 20. In combination, a relatively stationary contact, a movable contact for engaging and disengaging the relatively stationary contact, electromagnetic means for operating the movable contact at frequent intervals, a spring arm fixed at one end and carrying the relatively stationary contact near the other end and: biased to move the relatively stationary contact toward the movable contact and perm 't of the relatively stationary contacv in the oi direction when it is engaged by the movahi e tact, and a stop for limiting the movement of the spring arm and the relatively stationary contact toward the movable contact, said spring arm being ribbed throughout a portion of its length to strengthen the ribberi portion and to limit bending of the spring arm to the unribbed portion whereby a wiping action is produced between said movable relatively stationary contacts.

21. in combination, e. resilient reecl fixed at one end and movable at the other end, a permanent magnet, producing a magnetic field and arranged in its entirety in association with the movable end of the resilient reed, electromagnetic means including coil located in entirety adjacent is can of the resilient reed for creating rig magnetic which reacts with tent requiring; correction Petey common that error apps that produced by the permanent magnet for vibrating the resilient reed, a relatively stationary contact, and a movable contact remotely located with respect to the magnetic fields pro. duced by said permanent magnet and electromagnetic means and operated by the resilient reed for engaging and disengaging the relatively stationary contact.

, FREDERICK W. SIDE.

REFERENCES CITEB The following references are of file of this patent:

UNITED STATES PATENTS record in the Number 591317. 3. "WWW". 17, 1911") FREDERICK W. a

are in the printed specification of the ab as follows: Column 16, line 14, claim 10, I contacts before the period insert and a pair of adjustaie stops 7! Zimiaz'agr movement" of the spring arms 8; and that the said Letters Patent .& same may conform to the record oi"; the case in the Patent Silos. S'Signeo this 23rd d9, of September, A. D 1911?,

THOMAS mu l1 ti'ommtsa cmr of Assistan 

